Copying welding equipment

ABSTRACT

In the tracking welder, left and right side wheels are supported rotatably by a pair of bearing units that are pivotally attached on a carriage, and this carriage is provided with a driving source for running the carriage, a transmission system for transmitting a rotational motion of the driving source to the left and right side wheels, a welding torch, a sensor for detecting a route to be welded, a track-controlling motor to be rotate in forward and backward directions in response to a detection signal of the sensor, and a steering system for turning the bearing units in an amount corresponding to a rotational amount of the track-controlling motor. According to this tracking welder, it is possible to automatically perform various kinds of welding including not only fillet welding of a corner between horizontally placed steel plate and web plate erected on the steel plate, but also butt welding of steel plates, for example.

TECHNICAL FIELD

This invention relates to a welding apparatus and more particularly to atracking welder of which a carriage is so structured as to travel alonga predetermined welding line together with a welding torch mountedthereon.

BACKGROUND ART

When fillet welding of a corner of metallic plates is carried out byrunning the carriage mounted with the welding torch, the travelingdirection of the carriage should be controlled so that the welding torchmay travel along the welding line.

FIG. 14 illustrates an example of the conventional tracking welders. Ina case of fillet welding of the corner made by a virtually horizontallyplaced steel plate (a) and a steel web plate (b) erected on the steel(a), a self-travelable carriage (d) mounted with a welding torch (c) isplaced on the steel plate (a), and the welding of the corner isautomatically performed with the welding torch (c) at the same time ofrunning the carriage (d) along a tracking face, that is the web plate(b).

The carriage (d) is mounted with a front tracking roller (e) projectingtoward the tracking face (the web plate) (b) and a rear tracking roller(f) projecting at a long distance as compared with the front trackingroller e, and by running the carriage (d) in direction (g) slightlyinclined toward the tracking face (the web plate) (b), the fronttracking roller (e) and the rear tracking roller (1) become to be alwayscontact with the tracking face (the web plate) (b), and thus a distancebetween the welding torch (c) and the corner is kept constant.

However, as for the above-mentioned conventional tracking welder, whileit is possible to automatically weld the corner between the horizontallyplaced steel plate (a) and the web plate (b), there is a problem in thatsuch the machine is not available in a case the web plate (b) does notexist (in a case of butt welding, for example).

Moreover, even when welding the corner by utilizing the erected wall(b), there still remains a problem of limitation in the travelingdirections of the carriage (d), and it is impossible to perform weldingby running the carriage in the reverse direction from the arrow (g).

Furthermore, since the carriage (d) gradually approaches the web plate(b) while traveling, the wheels of the carriage (d) tend to be pushedback by the tracking rollers (e) and (f), and always slip in the lateraldirection, thereby causing the strong frictional resistance and makingthe carriage (d) not to travel so smoothly. Further, since the twotracking rollers (e) and (f) press the web plate (b) while the carriage(d) is traveling, there is another problem of a danger in that the webplate (b) pushed by the rollers (e) and (f) might come off from thesteel plate (a) in a case where the web plate (b) is temporally tackedon the steel plate (a), and it becomes subject to solve these problems.

DISCLOSURE OF THE INVENTION

The present invention has been achieved in view of the aforementionedproblems in the conventional arts, and it is an object to provide atracking welder, which is widely applicable in the welding of variousparts other than just a corner, which is able to perform welding evenwhen the traveling direction of the carriage is reversed, and further,which can perform welding smoothly along the predetermined route withoutcausing compulsive slipping to the wheels of the carriage while it istraveling.

The very investors found out that the above objects are attainable bysetting a steering system to a carriage and controlling it, and thuscomes to accomplish the present invention through their diligentscrutiny.

The tracking welder according to the present invention is characterizedby supporting left and right side wheels by a pair of bearing unitsattached pivotally on a carriage, and providing a driving source forrunning the carriage, a transmission system for transmitting arotational motion of the driving source to the left and right sidewheels, a welding torch, a sensor for detecting a welding line, atrack-controlling motor to be rotate in forward and backward directionsin response to a detection signal of the sensor, and a steering systemfor turning the bearing units in an amount corresponding to a rotationalamount of the track-controlling motor on the carriage.

Further, in the first preferred embodiment of the tracking welder in thepresent invention, the transmission system is characterized bycomprising a hollow outer cylinder rotatably supported on the carrier tobe transmitted with the rotational motion of the driving source, anintermediate shaft disposed in the hollow of the outer cylinder andconnected with axles of the wheels through universal joints at both endsthereof, and a transmission pin passing through an oval hole formed inthe intermediate shaft and engaged to the outer cylinder at both endsthereof, as the second preferred embodiment of the tracking welder inthe present invention, the steering system is characterized bycomprising a pair of arm bolts protruding from outer faces of therespective bearing units, a connection bar pivotally connected with onepair of arm bolts at both ends thereof, and a lever secured on an outputshaft of the track-controlling motor and engaging with one of the armbolts at a free end thereof, and as the third preferred embodiment ofthe tracking welder in the present invention, it is characterized byfurther providing a suction system for attracting the carriage toward acarriage-running face so as to enable the carriage to travel on therunning face.

Furthermore, another tracking welder of the present invention is awelding apparatus for welding works made of non-magnetic metal with eachother, and is characterized by comprising a carriage traveling in astate of holding a welding torch, and a suction system for attractingthe carriage toward the works so as to enable the carriage to travel,and the suction system is provided with a flat base made of magneticmetal, and having a carriage-running face and a traveling route-settingmeans, a flexible suction cup formed with an aperture and fitted onreverse side of the carriage-running face of the base in a state ofdirecting the aperture toward the opposite direction of thecarriage-running face, a suction source for sucking air in the suctioncup, and a magnet disposed on the carriage for preventing the carriageto fall.

In the tracking welder of the present invention, the rotational motionof the driving source is transmitted to the wheels through thetransmission system, thereby running the carriage. When the sensormounted on the carriage detects displacement of the welding torch fromthe predetermined welding line, the tracking-controlling motor rotatesin response of the detection signal from the sensor, and the bearingunits turn in accordance with the rotational amount of thetrack-controlling motor through the steering system, whereby thedirection of the wheels is corrected according to the turn of thebearing units, and the carriage comes to travel along the predeterminedroute, in such manner the welding is completed without deviating fromthe predetermined welding line.

Further, in the tracking welder of the first preferred embodiment in thepresent invention, having the above described construction, the outercylinder supported by the carriage rotates by the rotation of theprimary travel drive rotates, and the rotation of the outer cylinder istransmitted to the intermediate shaft by way of the transmission pin,whereby the rotation of the intermediate shaft is now transmitted to thewheels through the universal joints, and thus the carriage comes totravel smoothly.

Furthermore, in the tracking welder of the second preferred embodimentin the present invention, provided with the aforementioned construction,when the sensor detects the displacement amount of the welding torchfrom the welding line while the carriage is traveling, thetrack-controlling motor rotates on basis of on the detection amount, thelever fixed on the output shaft of the track-controlling motor pressesone of the arm bolts, thereby transmitting this force to another armbolt through the connection bar, and in this way, both arm bolts come toturn in the same amount. Also, the bearing units coupled with the armbolt turn together with the wheels, and the direction of the wheels isautomatically corrected, whereby the carriage comes to travel along thepredetermined route.

As already mentioned, in the case where transmission system of drivingforce is provided with the a hollow outer cylinder rotatably supportedon the carrier to be transmitted with the rotational motion of thedriving source, the intermediate shaft disposed in the hollow of theouter cylinder and connected with the axles of the wheels through theuniversal joints at both ends thereof, the direction of the wheels canbe changed without being impeded by the intermediate shaft because theuniversal joints are provided between the intermediate shaft andrespective wheels, and the intermediate shaft is disposed so as to bepossible to swing around the transmission pin serving as a fulcrum.

Further, in the tracking welder of the third preferred embodiment in thepresent invention, which is further provided with the suction system forattracting the carriage toward the carriage-running face so as to enablethe carriage to travel on the running face, it is possible to hold thecarriage on the carriage-running face, thereby enabling the welder toperform butt welding of works made of non-magnetic metal and multi-layerwelding at a corner of works, for example, and application fields ofthis tracking welder come to be increased.

Furthermore, in the second tracking welder of this invention, which ismost suitable for butt welding of non-magnetic metal works, the base isadsorbed on the works by sucking air in the suction cup using thesuction source of the suction system, thereby completing setting for theworks, on the other hand, the adsorption state of the base on the worksis released by stopping the operation of the suction source of thesuction system and introducing air into the suction cup, whereby thebase becomes removable. In this manner, arrangements and withdrawals asa whole become easier and possible to be completed in a short time. In apreferred embodiment of the second tracking welder in the presentinvention, the setting of the route for the carriage becomes availablesimple.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a bottom view illustrating an embodiment of the trackingwelder according to this invention;

FIG. 2 is an explanatory view from the direction of arrow A in FIG. 1;

FIG. 3 is an explanatory view from the direction of arrow B in FIG. 1;

FIG. 4 is an explanatory view from the direction of arrow C in FIG. 1;

FIG. 5 is a sectional view along section lines D—D of FIG. 4;

FIG. 6 is a sectional view along section lines E—E of FIG. 5;

FIG. 7 is an explanatory view illustrating the action of the steeringsystem,

FIG. 8 is an explanatory view illustrating a state of butt welding usingthe tracking welder according to the embodiment of this invention;

FIG. 9 is a perspective view illustrating another embodiment of thetracking welder according to this invention;

FIG. 10 is a side view of the tracking welder shown in FIG. 9;

FIG. 11 is a front view of the tracking welder shown in FIG. 9;

FIG. 12 is a perspective view illustrating the other embodiments of thetracking welder according to this invention;

FIG. 13 is a side view illustrating other embodiment of the trackingwelder according to this invention; and

FIG. 14 is a top view illustrating the action of the conventionaltracking welder.

BEST MODE FOR CARRYING OUT THE INVENTION

The present invention will be described in detail on basis ofembodiments thereinafter, however this invention is not limited to theseembodiments.

EXAMPLE 1

An embodiment of the tracking welder according to this invention isshown in FIG. 1 to FIG. 8.

A carriage 1 is composed of a rectangular base plate 1 a and rectangularframe 1 b disposed in the center on the bottom face of the base plate 1a as shown in FIG. 1 and FIG. 4, and a pair of wheels 2, which functionsas front wheels on left and right side, is supported by bearing units 3,respectively.

The bearing unit 3 is provided with sidewalls 3 b extending downwardfrom the respective ends of an upper plate 3 a, and a back wall 3 cextending downward from the back end of the upper plate 3 a. A thrustpin 4 protruding from the upper face of the upper plate 3 a is insertedinto a bearing 5, which is fitted into a through hole formed in thecarriage 1, and the end of the thrust pin 4 projecting out from thethrough hole is locked by a stopper ring 6.

As shown in FIG. 5, bearings 7 are fitted into holes formed through theboth sidewalls 3 b of the bearing unit 3, and an axle 2 a of the wheel 2is supported by these bearings 7. Accordingly, the wheels 2 arestructured to rotate around the axles 2 a, and so designed as to be ableto change the running direction around the thrust pins 4.

The bearing unit 3 is provided with an arm bolt 8 on the back wall 3 cthereof. Further, a motor 9 is mounted on the upper face of the carriage1 as a driving source, as shown in FIG. 4, and attached with a sprocket10 on an output shaft thereof.

As also shown in FIG. 8, carriage 1 is mounted with a welding torch Tand a sensor 30 for detecting displacement by applying a laser beam tothe welding line L, and a track-controlling motor 11 is attached on theouter wall of the frame 1 b, which rotates by receiving a detectionsignal from the sensor 30 as shown in FIG. 2. The motor 11 fixed with alever 12 on the output shaft thereof.

An optical axis LB of the sensor 30 is focused to the welding line Lthrough a turning operation of a knob 31, and the welding torch T is sostructured as to weave within a range shown by arrows around an axis P.

As also shown in FIG. 3, the free end of the lever 12 is engaged withthe arm bolts 8 protruding from one of the bearing units 3, and the twoarm bolts 8 are pivotally connected to respective ends of a connectionbar 14 through forked fittings 13 secured on the free ends of the armbolts 8.

Namely, the track-controlling motor 11 works on basis of the signal fromthe sensor 30, thereby swinging the lever 12 in the normal or thereverse directions, and the swing of the lever 12 is transmitted to thebearing units 3 of the left and right sides through the arm bolts 8,thereby changing the direction of the left and right side wheels 2together with the bearing units 3 toward the left or right side from thetraveling direction of the carriage 1. In this manner, the steeringsystem is composed.

As also shown in FIG. 6, a pair (left and right) of cylinder brackets 15are fixed on the bottom face of the base plate 1 a of the carriage 1with bolts 16, a hollow outer cylinder 18 is rotatably supported bybearings 17 fitted into through holes of the cylinder brackets 15, and asprocket 19 disposed at one end of the outer cylinder 18 is connectedwith a sprocket 10 disposed to the output shaft of the motor 9 through achain 20.

A chain 25 is stretched between a sprocket 21 disposed at another end ofthe outer cylinder 18 and a sprocket 24 disposed to an axle 23 of rearwheels 22. As shown in FIG. 5, the intermediate shaft 26 disposed in thehollow of the outer cylinder 18 is connected to the axles 2 a of thefront wheels 2 through universal joints 27 at the respective endsthereof, and a transmission pin 29 is passed through an oval hole 28formed in the middle of the intermediate shaft 26 and engaged to thehollow outer cylinder 18 at the both ends thereof.

That is to say, when the motor 9 starts, the rotational motion of themotor 9 is transmitted to the outer cylinder 18 through the sprocket 10,the chain 20, and the sprocket 19, the rotational motion of the outercylinder 18 is transmitted to the intermediate shaft 26 through thetransmission pin 29, whereby the front wheels 2 come to rotate and atthe same time, the rear wheels 22 also come to rotate by the powertransmitted to the rear axle 23 through the sprocket 21, the chain 25,and the sprocket 24, and in this way, the transmission system fordriving force is composed.

In this time, the universal joint 27 is disposed between the axle 2 a ofthe wheel 2 and the intermediate shaft 26 transmitting the power, andthe universal joint 27 is fitted to the intermediate shaft 26 with aplay, therefore the power of the intermediate shaft 26 is transmitted tothe wheels 2 smoothly even when correcting the direction of the wheels 2while traveling.

Furthermore, this tracking welder is provided with a suction system 40for attracting the carriage 1 on a carriage-running face F so as toenable the carriage 1 to travel, as shown in FIG. 4.

The suction system 40 is provided with a suction sleeve 41 disposed tothe carriage 1 to communicate with the inside of the frame 1 b, packing43 made of silicon rubber or so, attached on the lower end of the frame1 b through a bottom plate 42 and set in near contact with thecarriage-running face F, and a vacuum pump (not shown) working as asuction source and connected with the suction sleeve 41 through a hose.The suction system 40 is designed to attract the carriage 1 so that thecarriage 1 may travel on the carriage-running face F by actuating thevacuum pump and sucking air in the frame 1 b of the carriage 1.

As shown in FIG. 8, in a case of carrying out butt welding of steelplates, at first, the tracking welder is placed on the running face F ofthe steel plates in a state of directing the front wheels 2 toward thewelding direction (on the left side in FIG. 8). Then, the optical axisLB of the sensor 30 is adjusted with the welding line L by the turningoperation of the knob 31, and the welding torch T is approached to thestarting point of the welding.

Following suction of air in the inner part of the frame 1 b of thecarriage 1 to enable the carriage 1 to travel in a state of beingattracted on the carriage-running face F by actuating the vacuum pump, aswitch on a cover (not shown) provided on the carriage 1 is operated onto supply power to the motor 9. In this manner, the carriage 1 of thetracking welder comes to travel over the welding of the predeterminedwelding line L by rotating the wheels 2 at the same time of making thewelding torch T to weave in the range of arrows around the axis P.

Then, when the sensor 30 on the carriage 1 detects deviation(displacement) of the present traveling route of the carriage 1 from thepredetermined welding line L, the track-controlling motor 11 rotates asmuch as an amount corresponding to the displacement amount in responseto the detection signal from the sensor 30, the lever 12 fixed to thetrack-controlling motor 11 presses the arm bolt 8 by the rotation of themotor 11, whereby the direction of the wheels 2 is correct according tothe turn of the bearing units 3 pushed by the arm bolts 8, and thuscarriage 1 of the tracking welder comes to travel always withoutdeviating from the predetermined welding line L.

Under this operation, as illustrated in FIG. 7, since the universaljoint 27 is disposed between the axle 2 a of the wheel 2 and theintermediate shaft 26 transmitting the power, and the universal joint 27is fitted with the intermediate shaft 26 with the play, the intermediateshaft 26 just inclines slightly when the direction of the wheels 2 iscorrected during the travel, so that it is possible to smoothly transmitthe power to the wheels 2.

In addition to above, the tracking welder having the aforementionedconstruction may be also mounted with an equalizer system.

EXAMPLE 2

Another embodiment of the tracking welder according to the presentinvention is shown in FIG. 9 to FIG. 11.

The tracking welder shown in FIG. 9 is a welding apparatus for usingbutt welding of works W made of non-magnetic metal, such as aluminum andstainless steel. A suction system 60 in this tracking welder, whichattracts a carriage 51 mounted with a welding torch 54 toward the worksW so as to enable the carriage 51 to travel, is mainly composed of aflat base 62 made of magnetic metal and provided with a carriage-runningface 62 a and a tracking wall 62 b as a traveling route-setting means, aflexible suction cup 61 fitted on the reverse side (lower side in thefigures) of the carriage-running face 62 a of the base 62 in a state ofdirecting an aperture 61 a toward the opposite direction of thecarriage-running face 62 a, a suction pump (suction source) 63 connectedwith a suction port 61 b of suction cup 61 through a hose 64 to such theair in the suction cup 61, and a magnet (not shown) disposed on thecarriage 51 for preventing the carriage 51 from falling as shown in FIG.10 and FIG. 11.

The suction system 60 is so designed as to enable the base 62 to beattached not only on the upper face of the works W, but also on the sideface and the bottom face of the works W by actuating the suction pump 63and sucking air in the suction cup 61, and the other hand, as to enablethe base 62 to be easily detached from the works W by stopping theoperation of the suction pump 63 and opening the inside of the suctioncup 61 into the atmosphere.

In this case, the carriage 51 is installed with a pair of the trackingarms 51 a on the side face thereof, and so structured as to travel alongthe predetermined running route by setting the carriage 51 toslide-contact the tracking arms 51 a with the tracking wall 62 b of thebase 62 in a state of attaching the base 62 to the works W so that thetracking wall 2 b positioned at the side edge of the base 62 may besituated along the butt welding line L of the works W.

In this tracking welder, the flat base 62 made of magnetic metal andpossible to set the traveling route of the carriage 51 is adsorbed onthe works W, and the setting of the base 62 against the works W iscompleted by actuating the suction pump 63 of the suction system 60 andsucking air in the suction cup 61 after placing the base 62 on the worksW so as to situate the tracking wall 62 b along the butt welding line Lof the works W. On the other hand, the adsorption state of the base 62on the works W is cancelled and the withdrawal of the base 62 becomespossible by stopping the operation of the suction pump 63 of the suctionsystem 60, and the respective operation in arrangements and withdrawalsis completed easily in a short time, accordingly workability of the buttwelding comes to be improved remarkably.

Further in this welder, the traveling route of the carriage 51 is madeby the tracking wall 62 b of the base 62, therefore the setting of thetraveling route of the carriage 51 is done with the simple construction.

EXAMPLE 3

The other embodiment of the tracking welder according to the presentinvention is shown in FIG. 12. There are differences between this welderand the welder according to the preceding embodiment (Example 2) in thepoint that the base 62 is formed with rails 62 c as a travelingroute-setting means so as to run a carriage 51A along the predeterminedtraveling route by these rails 62 c as shown in FIG. 12, and thetracking welder according to this embodiment is the same as the welderaccording to the preceding embodiment excepting the construction asmentioned above.

Therefore, also in this welder, the respective operation in arrangementsand withdrawals is completed easily in a short time, accordinglyworkability of the butt welding comes to be improved remarkably,additionally the setting of the traveling route of the carriage 51A isdone with the further simple construction since the traveling route ofthe carriage 51 can be set by the rails 62 c formed on the base 62.

EXAMPLE 4

FIG. 13 illustrates the other embodiment of the tracking welderaccording to the present invention. There are differences between thiswelder and the welders according to the preceding embodiments (Example 2and 3) in the point that the suction port 61 b of the suction cup 61 inthe suction system 60 is disposed on the carriage-running face 62 a ofthe base 62 in a position where the carriage 51 may travel withouthindrance and the suction port 61 b and the suction pump 63 areconnected through the hose as shown in FIG. 13, and the tracking welderaccording to this embodiment is the same as the welders according to thepreceding embodiments excepting the construction as mentioned above.

Also in this welder, the respective operation in arrangements andwithdrawals is completed easily in a short time.

In the aforementioned examples shown in FIG. 9 to FIG. 12, the cases areillustrated where the tracking welder according to this invention is seton the upper surface of the work W, however the present invention is notlimited merely to such the examples and it is also set the welder on theside face as shown in FIG. 13 (Example 4), or on the bottom face of thework W.

INDUSTRIAL APPLICABILITY

As described above, in the tracking welder according to the presentinvention, providing the aforementioned construction, an excellenteffect can be obtained in that it is possible to carry out various kindsof automatic welding, including butt welding of steel plates with eachother, without being limited only in fillet welding between the steelplate and the web plate erected on this steel plate unlike theconventional tracking welder.

Also, in a preferred embodiment of the tracking welder according to thepresent invention, providing the aforementioned construction, thetraveling direction is not limited in just one direction, but it ispossible to apply welding from the reverse direction. In anotherpreferred embodiment of the tracking welder according to the presentinvention, having the aforementioned construction, it is possible tosmoothly perform welding along the predetermined route without causingunnatural slipping to the wheels while the carriage is traveling.

Furthermore, in the other preferred embodiment of the tracking welderaccording to the present invention, providing the aforementionedconstruction, it comes further to perform, for example, butt welding ofthe works made of non-magnetic metal, and it becomes possible to realizeenlargement of applicable fields of this tracking welder.

Moreover, in the other preferred embodiment of the tracking welderaccording to the present invention, it is possible to carry out therespective operation in arrangements and withdrawals simply in a shorttime in butt welding of the works made of non-magnetic metal, andconsequently, possible to realize remarkable improvement of theworkability of the butt welding. Further in the other preferredembodiment of the tracking welder according to the present invention, itis possible to set the running route of the welding carriage withoutcomplicating the construction, in addition to the same effects obtainedin the aforementioned tracking welders.

1. A tracking welder for automatically welding works along apredetermined welding line, comprising: a carriage provided with leftand right side wheels rotatably supported respectively through a pair ofbearing units pivotally mounted thereon; a driving source mounted on thecarriage for driving said carriage; a transmission system mounted on thecarriage for transmitting a rotational motion of said driving source tosaid left and right side wheels; a welding torch mounted on thecarriage; a sensor mounted on the carriage for detecting the weldingline; a track-controlling motor mounted on the carriage and rotating inforward and backward directions in response to a detection signal fromsaid sensor; and a steering system mounted on the carriage for turningsaid bearing units as much as an amount corresponding to a rotationalamount of said track-controlling motor; wherein said transmission systemis provided with: a hollow outer cylinder rotatably supported on saidcarriage to be transmitted with the rotational motion of the drivingsource; an intermediate shaft disposed in the hollow of said outercylinder and connected with axles of said wheels through universaljoints at both ends of the outer cylinder; and a transmission pinpassing through an oval hole formed in said intermediate shaft andengaged to said outer cylinder.
 2. A tracking welder as set forth inclaim 1, wherein said steering system is provided with: a pair of armbolts protruding from outer faces of said respective bearing units; aconnection bar pivotally connected with said one pair of arm bolts atboth ends thereof; and a lever secured on an output shaft of saidtrack-controlling motor and engaging with one of said arm bolts at afree end thereof; and wherein said welder is further provided with asuction system for attracting the carriage toward a carriage-runningface so as to enable the carriage to travel on the running face.
 3. Atracking welder for automatically welding works made of non-magneticmetal along a predetermined welding line, comprising: a carriagetraveling in a state of holding a welding torch; and a suction systemfor attracting said carriage toward the works so as to enable thecarriage to travel, wherein said suction system is provided with a flatbase made of magnetic metal, and having a carriage-running face and atraveling route-setting means; a flexible suction cup formed with anaperture and fitted on said base on a side reverse from thecarriage-running face in a state of directing the aperture toward anopposite direction of the carriage-running face; a suction source forsucking air in said suction cup; and a magnet is disposed on thecarriage for preventing the carriage to fall.
 4. A tracking welder asset forth in claim 3, wherein said base is provided with a tracking wallor a rail thereonto as said traveling route-setting means.